It is the dawn of a new day at Prairie Crossing in
Grayslake, a place that self-consciously calls itself “A Conservation
Community.” The hypothetical Smith
family, is committed to conservation as solution, unlike Vice President Dick
Cheney, who famously said, “Conservation may be a sign of personal virtue, but
it is not a sufficient basis for a sound, comprehensive energy policy.” Mr.
Smith takes Metra into the city on weekdays, while Mrs. Smith drives a Prius.
They live in a modest green home, built using the best passive technologies to
reduce their energy consumption. Prairie Crossing is a community that is
designed using the best planning approaches championed by the Congress on New
Urbanism.
The streets of
Prairie Crossing are narrow and the houses are built closely together, making
it convenient to walk to the small town center,
The hypothetical
Smith’s are hypothetically green. They have made progress towards a green
future. Where a normal suburban household consumes 240 million BTU’s of energy
per year to maintain the house and for transportation, the Smith’s have likely
reduced this number to 164 MBTU’s.
But there are
disquieting truths lying just below the surface of Prairie Crossing. Where in a
normal suburban household 125 MBTU’s of the 240 total energy is used for
transportation, in the Smith’s case, roughly half of their energy use is still
devoted to transportation. Even more discouraging, if the normal suburban
house—not a particularly green one—is built in a city, the transportation
component of household energy use drops to 28 MBTU’s, bringing the overall
energy use down to 143 MBTU’s. In other words, the location of the house has a
far greater impact on household energy use than all the efforts and
expenditures to build green and drive green.
On the other hand,
if you build the Smith’s green house on an urban lot, the household energy use
drops to 89 MBTU’s. Even better, if you lease or buy in a multi-family green
urban building, energy consumption drops to 62 MBTU’s or 25 percent of the
typical suburban household.
The
energy-efficiency of multi-family housing is often overlooked. Where a single
family house usually has a one-to-one ratio between interior and exterior
surface area, which gains heat in the summer and looses heat in the winter, the
typical apartment has at most one or two edges exposed to the weather and is
surrounded above and below by other apartments.
In an earlier
article, I discussed how sprawl is both an age-old phenomenon that began during
the
In a variety of
forms, the latest thinking about energy consumption and global warming is
centered around what has been called the carbon challenge. The hypothesis is
that we should as a culture accept the challenge to reduce carbon generation in
a series of ever more stringent stages over the next 30 years. Carbon
generation is a measure of both energy use and the pollution that scientists
see as the cause of global warming. The ultimate goal is for every household to
become carbon neutral. It’s clear the easiest way to respond to the carbon
challenge is to move back into the city.
Urban residents in multi-family buildings have a shorter
distance to travel to meet the carbon challenge. Increasing efficiency of both
rapid transit and cars, combined with smarter building design, should allow these
households to meet this goal. For owners of single family buildings, they will
have to work harder to meet their carbon budgets —probably requiring active
technologies such as the use of photo-voltaic (PV) cells to produce energy.
For suburban residents,
it will be a far more difficult exercise. We can already see both the
potentials and the problems. The efficiency of buildings and everything they
contain are improving rapidly. The
future single family house, both urban and suburban, will probably look much
like it does today except it will lose much less heat in the winter and gain
much less heat in the summer. Every personal device will use a fraction of the
energy that is used today.
The biggest
problem is transportation. Despite our best efforts, it still takes a great
deal of energy to move things from place to place. Prairie Crossing is a
conservation community compared to other suburban developments, but can such an
approach ever meet the carbon challenge?
Published: April 06, 2008
Issue: 2008 Spring Green Issue